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Mecanismo de inserción de propileno utilizando catalizadores de titanio basados en bis ((phenoxyimine): una inusual
Phillip D Hustad1, Jun Tian, Geoffrey W Coates
1Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, USA.
Journal of the American Chemical Society
|April 4, 2002
Resumen
Este estudio revela una regioselectividad única en la inserción de propileno utilizando catalizadores de titanio basados en fenoxiamina. Estos catalizadores insertan exclusivamente propileno con 2,1-regiocímico, un hallazgo novedoso en la polimerización.
Área de la Ciencia:
- Química de Polímeros La química de los polímeros es la química de los polímeros.
- Química organometálica Química orgánica de los metales.
Sus antecedentes:
- La regioselectividad de inserción de propileno es crucial para las propiedades del polímero.
- Los catalizadores de titanio son ampliamente utilizados en la polimerización de olefinas.
Objetivo del estudio:
- Para investigar la regioselectividad de la inserción de propileno utilizando catalizadores de titanio basados en fenoxiamina.
- Identificar nuevos sistemas catalíticos con exclusiva 2,1-regioselectividad.
Principales métodos:
- Síntesis y caracterización de complejos de titanio basados en bis (fenoximina).
- Análisis de grupos finales de polipropileno producido mediante inserción catalítica.
- Utilizando la ciclo polimerización y la copolimerización de etileno/propileno.
Principales resultados:
- Los catalizadores de titanio basados en fenoxiamina exhiben una reversión en la regioselectividad de inserción de propileno.
- Química exclusiva de 2,1-región observada en la inserción de propileno en alquilos secundarios de titanio.
- La inserción inicial en el hidruro de titanio muestra una alta 1,2-regiochemistry.
Conclusiones:
- Los complejos de titanio basados en bis (fenoximina) son los únicos catalizadores conocidos del Grupo IV que demuestran exclusivamente 2,1-regioselectividad para la inserción de propileno.
- Los hallazgos ofrecen nuevos conocimientos sobre el diseño de catalizadores para microestructuras de polímeros controlados.
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